Preheat the oven to 425°F. Line a large baking sheet with parchment paper.
Combine the squash, sausage, onion, peppers, olive oil, and paprika in a large mixing bowl and toss until well combined.
Spread the sausage and vegetables onto the baking sheet in an even layer. Transfer the baking sheet to the oven and roast for 35-40 minutes, tossing about halfway through, until the squash is tender.
Meanwhile, combine all the apple cider vinaigrette ingredients together in a small jar. Cover the jar with a tight-fitting lid and shake vigorously until emulsified.
Divide the spinach between two plates and top with the roasted sausage and vegetables. Serve with apple cider vinaigrette, to taste.